Collectively, we report the efficacy of apremilast in the reduction of epidermal thickening, leukocyte infiltration and expression of key proinflammatory cytokines in the K5.Stat3 mouse model of psoriasis, further supporting the ability of this PDE4 inhibitor to efficiently target key clinical, histopathological and inflammatory features of psoriasis. The gene discussed is PDE4A; the disease is psoriasis.